	//工具类
	var util = {
		//随机数成功
		numRandom: function() {
			return Math.random().toString();
		},
		//向上取整
		ceil: function(num){
			return Math.ceil(num);
		},
		//向下取整
		floor: function(num){
			return Math.floor(num);
		},
		//四舍五入
		round:function(num){
			return Math.round(num);
		}
	};